The 160-mile-long Garlock fault that runs northeast-southwest along the Mojave Desert in Southern California has begun moving for the first time on record, according to a study published Thursday by Caltech scientists and based on new satellite radar images.

"This is surprising, because we've never seen the Garlock fault do anything. Here, all of a sudden, it changed its behavior," lead author of the study Zachary Ross, an assistant professor of geophysics at Caltech, is quoted as saying by the Los Angeles Times. "We don't know what it means."

According to the scientists, a portion of the fault has shifted about 0.8 inches since July, when two earthquakes took place in the region. The 6.4-magnitude tremor that struck 122 miles northeast of Los Angeles on July 4 was followed one day later by a powerful 7.1-magnitude earthquake that caused a fissure within the Little Lake fault zone in Southern California's Indian Wells Valley area.

Seismic activity in California appears to be heating up again. Could it be possible that the swarm of earthquakes that has hit San Francisco over the past couple of days is a precursor to a larger seismic event? The California coastline sits directly along the infamous "Ring of Fire", and scientists assure us that it is just a matter of time before "the Big One" hits the state. Of course most of the time when we talk about "the Big One", most people immediately envision a geography-altering earthquake in southern California, and we have been warned repeatedly that such an event is coming someday. However, northern California is quite vulnerable as well, and a repeat of the horrific 1906 San Francisco earthquake is definitely not out of the question. Today, the real estate in the San Francisco Bay Area is some of the priciest in the entire nation, but much of that real estate could potentially be reduced to rubble in just a matter of moments. Millions of Californians are literally living on a ticking time bomb, and at some point time will run out.

Scientists have discovered that the sea floor shakes during hurricanes and nor'easters, with a rumbling as strong as a magnitude 3.5 earthquake.

They've dubbed the phenomenon "stormquakes."

The scary sounding mash-up was detailed in research by Florida State University scientists published this week in the journal Geophysical Research Letters.

The shaking of the sea floor during hurricanes and nor'easters can last for days, according to the study. While fairly common, the quakes weren't noticed before because they were considered seismic background noise.

A stormquake is more an oddity than something that can hurt you, because no one is standing on the sea floor during a hurricane, said Wenyuan Fan, a Florida State University seismologist who was the study's lead author.

The combination of two frightening natural phenomena might bring to mind "Sharknado," but stormquakes are real and not dangerous.

Residents of San Francisco and the Bay Area were shaken from their sleep by a 3.9-magnitude earthquake. Luckily, this time the quake triggered only memes and videos from rudely awoken San Franciscans.

The tremor struck just 6km (3.7 miles) off the coast of Colma, just south of San Francisco, on Saturday morning, according to the US Geological Service. An earthquake of this magnitude is strong enough to cause minor damage, but typically results in only shaking and rattling of objects indoors.

It's not just the living that were disturbed from their sleep. Colma, the town closest to the epicenter, is home to more than 1.5 million dead bodies. Founded as a necropolis in 1924, the dead outnumber the living in Colma by nearly a thousand to one.

There is a whole lotta shaking going on in America right now, and many people are concerned about what that could potentially mean. Could it be possible that the U.S. is entering a more seismically active time? This week alone, we have seen earthquake swarms in Texas, Oklahoma, San Francisco and the New Madrid fault zone. Of course earthquakes happen every day, but to see so many earthquake swarms happen in such diverse places within such a compressed period of time is definitely unusual. And what makes this even more unusual is the fact that Rosh Hashanah just ended. In fact, the earthquake swarm that we just witnessed in Texas started on Rosh Hashanah with a magnitude 4.0 quake near the town of "Snyder"...

In just over 12 hours, Texas experienced not one earthquake, but four, experts say.

Three quakes were centerednear the town of Snyder — just south of the Texas panhandle — with a fourth centered near the Fort Worth area, according to the United States Geological Survey. The first and strongest of the cluster hit just after 4:45 p.m. Monday about 12 miles north of Snyder and measured magnitude 4.0.

That was the strongest earthquake in Texas so far this year, and it was followed by a magnitude 3.8 earthquake near Snyder, a magnitude 3.2 earthquake just south of Fort Worth, and a magnitude 2.5 earthquake near Snyder.

An area of southeast Missouri experienced five earthquakes in less than hour Monday morning, experts say.

It started with a 2.6 magnitude temblor around 11:18 a.m. near Lilbourn, a small city just north of Missouri's boot heel, according to the United States Geological Survey. A mere three minutes later, a 1.1 magnitude quake rumbled nearby.

Just before 11:30 a.m., a 2.7 magnitude quake rattled southwest of Lilbourn followed by a 1.8 magnitude quake only five minutes later, the USGS says.

It would be 23 minutes before the next quake, another magnitude 2.7, shook an area just west of Lilbourn, the USGS says.

All five quakes happened within a 40-minute window.

Comment: For more related articles on the New Madrid Seismic Zone see:

The country is situated in a region adjacent to the fast-moving Nazca Plate, which is characterised by high tectonic activity.

A 7.2-magnitude earthquake rocked Chile on Sunday, striking at a depth of 9.8 kilometres, according to the United States Geological Survey. The tremor struck at 15:57 (UTC), 67 kilometres west of the city of Constitucion.